6.1        Site Exploration

6.1.1            Survey Control

6.1.1.1          BWI Marshall Airport Surveying Monuments

Please refer to Appendix 2E - Survey Control Manuals.

 

NGS monumentation that has been damaged or destroyed should be reported to the National Geodetic Survey web page. In the event that the actual marker is separated from its setting, you can report the point as destroyed. To do so, please send the report on the destroyed mark to the NOAA. In addition, please submit proof of the mark's destruction via actual disk, rubbing, photo, or digital picture (preferred) to:

NOAA, National Geodetic Survey, N/NGS143

1315 East West Highway

Silver Spring, MD 20910

 

If you did not find the actual marker, then you should enter notes concerning evidence of its possible destruction as text records and select "Not recovered, not found" as the condition of mark.

 

Also, please immediately notify the Director of the Office of Engineering & Construction, Maryland Aviation Administration, to report damaged or destroyed monumentation.

 

6.1.1.2          Martin State Airport Surveying Monuments

A network of 9 survey control points, including 3 points established by NGS, have been established at Martin State Airport to provide a reliable and accessible system of control for all surveys performed on the airport. Please refer to Appendix 2E - Survey Control Manuals.

 

Consultants shall use the Martin State Airport Survey Control for all design and construction projects. All project surveys must be tied to the Martin State Airport Survey Control Network shown on the Survey Control Drawing and described in the Survey Control Manual. All contract drawing sets must contain the Martin State Airport Survey Control Plan Sheet and a 2nd geometric layout sheet containing the specific geometric layout and coordinate data for the project. This drawing shall also include any and all points set by the contractor for the specific project stating traverse closures and which Martin State Airport control points were used.

 

The survey control for Martin State Airport is based horizontally on the Maryland State Plane Coordinate System which is tied to the North American Datum of 1983 (NAD 83), and vertically on the North American Vertical Datum 1988 (NAVD 88). Data supplied in the manual meets or exceeds 1st order horizontal survey control accuracies and is equal to or less than 3rd order vertical accuracies as indicated on the individual monument recovery sheet. All monuments are cast in place concrete, 48” deep with aluminum disks stamped “Martin State Airport – Survey Control”, and with a point ID.

 

All monuments are described on monument recovery sheets. Each monument recovery sheet contains “How to reach” descriptions for each control point, coordinates, elevations, and pictures of each monument as well as reference sketches. The scale factor given on the recovery sheet is the measure of the linear distortion that has been mathematically imposed on ellipsoid distances so they may be projected onto a plane. These monuments were set in the fall of 2005 and have a stability rating of “C” points subject to surface motion.

 

Elevations of monuments are based on the North American Vertical Datum of 1988 (NAVD88). Elevations are derived from GPS observations of NGS benchmark stations MARTAIR AZ (a third order vertical monument), CLOVER (a second order vertical monument), GIS58 (a third order vertical monument), and GIS70 (a third order vertical monument). Elevations are in U.S. Survey Feet.

 

The consultant is responsible for quality control checking of all new and existing monumentation prior to using the monuments in accordance with standard survey practices. Please notify the Airport Operations Manager of Martin State Airport (410-682-8826) and the Director of MDOT MAA’s Office of Engineering & Construction of damaged and destroyed monumentation immediately.

 

6.1.2            Subsurface Utility Engineering (SUE)

Refer to Volume 1, Section 1.5.

 

6.1.3            Geotechnical Investigations

The Consultant shall develop a program to perform subsurface exploration and laboratory testing in the area of any proposed construction. The Consultant shall describe the geotechnical exploration and testing methodology as part of the cost proposal required for the project. The explanation shall include technical issues to be resolved, field and laboratory methods to be used, estimated number and depths of borings/corings, and other field methods, estimated laboratory testing, and reporting methods.

 

Before performing any field work, the Consultant shall prepare a detailed work plan including coordination with stakeholders such as Airport Operations and the preparation of Tenant Information Advisories. The work plan shall include proposed boring/coring locations, details of investigation methods, coordination issues, and reporting schedule and the Consultant shall be responsible for identifying, field locating and avoiding all utilities in the vicinity of any proposed borings prior to drilling. Any utility discrepancies found shall be reported to the MDOT MAA Task Manager. Repair of any utility damaged by the Consultant shall be the Consultant’s responsibility. The work plan shall be submitted to the MDOT MAA Project Manager for review and approval before any field work is performed.

 

The Consultant shall stipulate in their work plan that approximately 50% of proposed cores be performed specifically in areas displaying pavement distress. Full-depth cores are to be extracted unless directed otherwise. All cores taken will be used to evaluate the appropriate depth of milling and repairs, where applicable. The core results shall include location, thickness, and condition (crack depth, debonding, stripping, partial/full disintegration etc.) of the extracted cores along with the underlying material(s). The core pictures shall depict clear and actual in-situ conditions.

 

When only pavement coring is to be performed, a “grab sample” of the unbound material directly beneath the pavement core is to be collected and stored in a container such as a zip lock bag or a sample jar. The material/soil type shall be reported based on visual classification.

 

All core/bore holes shall be backfilled/grouted with cementitious in-situ or borrow or patch material and compacted in multiple lifts, as appropriate. A minimum 12 in. depth from the existing pavement surface shall be patched with a fast setting concrete mix. Proper cleaning, patching, and compacting procedures shall be followed throughout to ensure a durable and satisfactory patch. Any improper or deficient patches shall be promptly repaired or replaced at no cost to MDOT MAA.

 

See Chapter 3.2 Deliverables by Design Phase for details on Geotechnical report deliverable requirements. See Chapter 3.7.2 Geotechnical Reports for details on Geotechnical report submission requirements.